Language in deafness: MRI makes predictions

Ezine

Predicting language

Magnetic resonance imaging (MRI) has been used to predict language improvement after a cochlear implant to treat deafness, the research could pave the way for brain specific therapy.

An international team based at The Chinese University of Hong Kong and the Ann & Robert H. Lurie Children’s Hospital of Chicago, USA, has developed a computer algorithm that can process MRI brain scans to reveal language ability potential in deaf children following cochlear implant. The algorithm is trained to find correlations between brain structure and language development. It could have far-ranging implications for children with developmental problems; details were published in the journal Proceedings of the National Academy of Sciences (USA).

“The ability to predict language development is important because it allows clinicians and educators to intervene with therapy to maximize language learning for the child,” explains cognitive neuroscientist Patrick Wong of The Chinese University of Hong Kong. “Since the brain underlies all human ability, the methods we have applied to children with hearing loss could have widespread use in predicting function and improving the lives of children with a broad range of disabilities” he adds.

Cochlear implant

The invention of the cochlear implant has revolutionized the treatment of profound deafness where hearing aids fail to give a child the ability to hear. It has been shown over the decades since they were first used that the earlier the implantation is carried out the better the outcome for the child. Indeed, while many children with a cochlear implant gain the ability to understand and develop speech, some children lag behind in development when compared to their hearing peers despite having received the implant as an infant or toddler. It is these children who perhaps need additional language and literacy teaching to help them achieve academic success, social and emotional well-being, and to boost their employment opportunities as adults.

“So far, we have not had a reliable way to predict which children are at risk to develop poorer language," explains Chicago's Nancy Young. "Our study is the first to provide clinicians and caregivers with concrete information about how much language improvement can be expected given the child’s brain development immediately before surgery." It is critical that healthcare workers have the ability to predict which children are at risk and this could be a critical first step to improving their chances of developing speech. "It will lay the groundwork for future development and testing of customized therapies," Young adds.

Bespoke versus off-the-shelf

Importantly, the notion of an off-the-shelf approach to intensive therapy is not only impractical but is also inadequate given these findings. It is important to now address the needs of those children most at risk so that they do not fall too far behind their peers born with normal hearing. Until now there has been an obvious gap between in language skills between deaf children and those with normal hearing. A new approach to therapy based at the individual level could improve lives significantly.

The differences arise because the body's successful development of hearing and spoken language depend on both the ear and the brain. The auditory areas of the brain in children with congenital deafness or early hearing loss will not follow abnormal patterns of brain development. “We used MRI to capture these abnormal patterns before cochlear implant surgery and constructed a machine-learning algorithm for predicting language development with a relatively high degree of accuracy, specificity and sensitivity,” Wong adds. “Although the current algorithm is built for children with hearing impairment, research is being conducted to also predict language development in other paediatric populations."